[?] [2727] [x64] AIMP: Alow system decoders with WASAPI Exclusive issue

[Dimon911]

Hi,

when "Allow system decoders usage"  option with WASAPI Exclusive (Event) Device enabled; playback stops after ~ 10-15 min. After playback is stopped it is impossible to start it again, play/pause button don't respond.

After restart AIMP playback work for next 10-15 min.

Happens mostly when AIMP is unfocused.

After disabling "Allow system decoders usage" no such issue is present with WASAPI Exclusive (Event) Device.

Changing device to DirectSound is working with "Allow system decoders usage".

[Artem]

I've failed to reproduce the issue on my side. What codecs are installed in your OSM

[Dimon911]

This behavior came with playing FLAC file. So i guess FLAC AUDIO Decoder MFT is a system decoder that relevant for this case.

(get-item (gwmi win32_codecfile).name).VersionInfo | select -Property fileversion, filen*, filed*

FileVersion                                               FileName                                                   FileDescription
-----------                                                --------                                                      ---------------
10.0.22621.1 (WinBuild.160101.0800)      C:\Windows\system32\IMAADP32.ACM         IMA ADPCM CODEC for MSACM
10.0.22621.1 (WinBuild.160101.0800)      C:\Windows\system32\MSYUV.DLL               Microsoft UYVY Video Decompressor
10.0.22621.1 (WinBuild.160101.0800)      C:\Windows\system32\MSGSM32.ACM         Microsoft GSM 6.10 Audio CODEC for MSACM
10.0.22621.2506 (WinBuild.160101.0800) C:\Windows\system32\MSRLE32.DLL           Microsoft RLE Compressor
10.0.22621.1 (WinBuild.160101.0800)      C:\Windows\system32\TSBYUV.DLL             Toshiba Video Codec
10.0.22621.1 (WinBuild.160101.0800)      C:\Windows\system32\MSADP32.ACM          Microsoft ADPCM CODEC for MSACM
1, 9, 0, 0401                                           C:\Windows\system32\L3CODECA.ACM        MPEG Layer-3 Audio Codec for MSACM
10.0.22621.1 (WinBuild.160101.0800)      C:\Windows\system32\MSVIDC32.DLL         Microsoft Video 1 Compressor
10.0.22621.1 (WinBuild.160101.0800)      C:\Windows\system32\IYUV_32.DLL            Intel Indeo(R) Video YUV Codec
10.0.22621.1 (WinBuild.160101.0800)      C:\Windows\system32\MSG711.ACM            Microsoft CCITT G.711 (A-Law and u-Law) CODEC for MSACM

  A cut from dxdiag
---------------------------
Media Foundation Transforms
---------------------------

[HKEY_LOCAL_MACHINE\Software\Classes\MediaFoundation\Transforms]

<category>:
  <transform friendly name>, <transform CLSID>, <flags>, [<merit>, ]<file name>, <file version>

Audio Decoders:
  Microsoft Dolby Digital Plus Decoder MFT, {177C0AFE-900B-48D4-9E4C-57ADD250B3D4}, 0x1, DolbyDecMFT.dll, 10.00.22621.7219
  MS AMRNB Decoder MFT, {265011AE-5481-4F77-A295-ABB6FFE8D63E}, 0x1, MSAMRNBDecoder.dll, 10.00.22621.0001
  WMAudio Decoder MFT, CLSID_CWMADecMediaObject, 0x1, WMADMOD.DLL, 10.00.22621.6133
  Microsoft AAC Audio Decoder MFT, CLSID_CMSAACDecMFT, 0x1, MSAudDecMFT.dll, 10.00.22621.6133
  A-law Wrapper MFT, {36CB6E0C-78C1-42B2-9943-846262F31786}, 0x1, mfcore.dll, 10.00.22621.7517
  GSM ACM Wrapper MFT, {4A76B469-7B66-4DD4-BA2D-DDF244C766DC}, 0x1, mfcore.dll, 10.00.22621.7517
  WMAPro over S/PDIF MFT, CLSID_CWMAudioSpdTxDMO, 0x1, WMADMOD.DLL, 10.00.22621.6133
  Microsoft Opus Audio Decoder MFT, {63E17C10-2D43-4C42-8FE3-8D8B63E46A6A}, 0x1, MSOpusDecoder.dll, 10.00.22621.0001
  Microsoft FLAC Audio Decoder MFT, {6B0B3E6B-A2C5-4514-8055-AFE8A95242D9}, 0x1, MSFlacDecoder.dll, 10.00.22621.4036
  Microsoft MPEG Audio Decoder MFT, {70707B39-B2CA-4015-ABEA-F8447D22D88B}, 0x1, MSAudDecMFT.dll, 10.00.22621.6133
  WMSpeech Decoder DMO, CLSID_CWMSPDecMediaObject, 0x1, WMSPDMOD.DLL, 10.00.22621.2506
  G711 Wrapper MFT, {92B66080-5E2D-449E-90C4-C41F268E5514}, 0x1, mfcore.dll, 10.00.22621.7517
  IMA ADPCM ACM Wrapper MFT, {A16E1BFF-A80D-48AD-AECD-A35C005685FE}, 0x1, mfcore.dll, 10.00.22621.7517
  MP3 Decoder MFT, CLSID_CMP3DecMediaObject, 0x1, mp3dmod.dll, 10.00.22621.2506
  Microsoft ALAC Audio Decoder MFT, {C0CD7D12-31FC-4BBC-B363-7322EE3E1879}, 0x1, MSAlacDecoder.dll, 10.00.22621.0001
  ADPCM ACM Wrapper MFT, {CA34FE0A-5722-43AD-AF23-05F7650257DD}, 0x1, mfcore.dll, 10.00.22621.7517
  Dolby TrueHD IEC-61937 converter MFT, {CF5EEEDF-0E92-4B3B-A161-BD0FFE545E4B}, 0x1, mfaudiocnv.dll, 10.00.22621.7376
  DTS IEC-61937 converter MFT, {D035E24C-C877-42D7-A795-2A8A339B472F}, 0x1, mfaudiocnv.dll, 10.00.22621.7376
Audio Encoders:
  LPCM DVD-Audio MFT, {068A8476-9229-4CC0-9D49-2FC699DCD30A}, 0x1, mfaudiocnv.dll, 10.00.22621.7376
  MP3 Encoder ACM Wrapper MFT, {11103421-354C-4CCA-A7A3-1AFF9A5B6701}, 0x1, mfcore.dll, 10.00.22621.7517
  Microsoft FLAC Audio Encoder MFT, {128509E9-C44E-45DC-95E9-C255B8F466A6}, 0x1, MSFlacEncoder.dll, 10.00.22621.4036
  WM Speech Encoder DMO, CLSID_CWMSPEncMediaObject2, 0x1, WMSPDMOE.DLL, 10.00.22621.6133
  MS AMRNB Encoder MFT, {2FAE8AFE-04A3-423A-A814-85DB454712B0}, 0x1, MSAMRNBEncoder.dll, 10.00.22621.0001
  Microsoft MPEG-2 Audio Encoder MFT, {46A4DD5C-73F8-4304-94DF-308F760974F4}, 0x1, msmpeg2enc.dll, 10.00.22621.6133
  WMAudio Encoder MFT, CLSID_CWMAEncMediaObject, 0x1, WMADMOE.DLL, 10.00.22621.6133
  Microsoft AAC Audio Encoder MFT, {93AF0C51-2275-45D2-A35B-F2BA21CAED00}, 0x1, mfAACEnc.dll, 10.00.22621.4974
  Microsoft ALAC Audio Encoder MFT, {9AB6A28C-748E-4B6A-BFFF-CC443B8E8FB4}, 0x1, MSAlacEncoder.dll, 10.00.22621.0001
  Microsoft Dolby Digital Encoder MFT, {AC3315C9-F481-45D7-826C-0B406C1F64B8}, 0x1, msac3enc.dll, 10.00.22621.2506

My firs thought: decoder will be disabled / suspended by inactivity  for some reason (system power / stand-by settings).. But it happens also when PC is used.. And AIMP is unfocused.

[Artem]

This behavior came with playing FLAC file. So i guess FLAC AUDIO Decoder MFT is a system decoder that relevant for this case.

Have you unloaded the BASS FLAC plugin?

[Dimon911]

No,

I don't know why are those not visible by gwmi win32_codecfile / dxdiag; But BASSFLac is enabled in AIMP. Those requests read registry entries, so I guess BASSFlac is AIMP internal only and not registered in windows registry.

The issue happens in combination with Alow system decoders and WASAPI Exclusive (Event)  with enabled BASSFlac, if I disable Alow system decoders playback works without interruption.

	BASSFLac ⋀ Alow system dec     |	BASSFLac ⋀ not(Alow system dec)
WASAPI (0.4s)	🤮	👍
DirectSound (0.2s)	👍	👍

I noticed also the buffer size of selected device.

[Artem]

Sure, our built-in plugins are not registered in registry, because it cannot be used by other applications. Anyway, system decoders are not used if the file can be decoded by built-in decoders. So, in this case the option should not affects to the result, but it does, that sounds so strange.

What is your OS version (exact build number)?

[Dimon911]

What is your OS version (exact build number)?

Win11  23H2 (OS build 22631.7517)

Not the latest. Are there some updates known, that have impact on audio decoder?

OMG just now at typing this, AIMP stopped playing with disabled  "Alow system dec" option.

the option should not affects to the result

You are 100% right!

Update the table 

	BASSFLac ⋀ Alow system dec     |	BASSFLac ⋀ not(Alow system dec)
WASAPI event (0.4s)	🤮	🤮
DirectSound (0.2s)	👍	👍

[Artem]

Have you tried WASAPI Exclusive Push variant? Is it has the same issue?

[Dimon911]

Yes,  with WASAPI Exclusive Push issue occurs much faster like in 2-3 minutes, basically playing one track.
By changing to Push, buffer size changes to 3.2 sec. (3200ms)

	BASSFLac ⋀ Alow system dec     |	BASSFLac ⋀ not(Alow system dec)
WASAPI event (0.4s)	🤮	🤮
WASAPI push (3.2s)	🤮🤮	🤮🤮
DirectSound (0.2s)	👍	👍

[Artem]

1) Please, start the app with /DEBUG key (you can modify path in shortcut settings in following way: "C:\Program Files\AIMP\AIMP.exe" /DEBUG)
2) Wait while playback will stopped due issue
3) Stop the playback
4) Try to start playback again (play/pause button should not respond)
5) Open Options Dialog and click "profile folder" link at bottom of the dialog
6) Send the AIMP.log file to me (you can attach it here or send it to a email)

[Dimon911]

I try to reproduce it with (event) no success yet, but push working fine (I mean the issue )

Please see attachment. I followed Your steps exactly. With an addition: I closed AIMP after step 5. (at line 2026.09.22 17:00:59.218)  Some click-sound appearing if after issue occurs I close AIMP.

In attached file WASAPI exclusive (push) mode is selected.

Uh. for some reason AIMP destroying used device at
Main   2026.09.22 16:56:58.296   D/ASO:   WASAPI: Destroy Device - WASAPI Exclusive (Push): Speakers (Klipsch R-51PM)


Another observation, if an issue accurs and I change device type for example to WASAPI Exclusive (event) playback continues.

[Dimon911]

I catch today after 48 min. the issue with WASAPI Exclusive (Event). It seems the time varies for some reason.

[Artem]

Uh. for some reason AIMP destroying used device at
Main   2026.09.22 16:56:58.296   D/ASO:   WASAPI: Destroy Device - WASAPI Exclusive (Push): Speakers (Klipsch R-51PM)

I catch today after 48 min. the issue with WASAPI Exclusive (Event). It seems the time varies for some reason.

The range of actions at this time indicates that the program was receiving a list of available output devices. What were you doing at that moment? Were you opening the program settings window?

[Dimon911]

What were you doing at that moment?

Browsing without media (partially audio). Normal behavior is: when I use AIMP in WASAPI Exclusive (event) any other source deny audio playback.

Were you opening the program settings window?

Nope, AIMP was the time after 2026.09.23 09:03:25  in  auto hidden, not focused state.

[Artem]

Please, try this build: https://aimp.ru/?do=download.file&id=21 and send log from it to me. I've added new entry points